Retrievable safety valve



Nov. 9, 1965 J. S. PAGE, JR

RETRIEVABLE SAFETY VALVE Filed May 26, 1961 Jet..

imwwikh imwxmh T5 Sheets-Sheet 1 @jaa/w Nov. 9, 1965 J. s. PAGE, JR

RETRIEVABLE SAFETY VALVE 5 Sheets-Sheet 2 Filed May 26. 1961 3 Sheets-Sheet 3 Nov. 9, 1965 J. s, PAGE, ,JR

RETRIEVABLE SAFETY VALVE Filed May 26, 1961 United States Patent O 3,216,501 RETRIEVABLE SAFETY VALVE John S. Page, Jr., 1450 El Mirador Ave., Long Beach, Calif.

Filed May 26, 1961, Ser. No. 112,886 19 Claims. (Cl. 166-72) The present invention relates to a subsurface safety valve for oil and gas wells and the like, and more particularly to a retrievable safety valve adapted to be run into and retrieved from the well on a wire line.

Among the primary objectives of the present invention is the provision of a retrievable safety valve of the above mentioned class which is so constructed that all of the perishable and moving parts of the valve are retrievable from the subsurface housing.

Another object is to provide a retrievable safety valve and housing therefor which housing is adapted to be installed in a tubing string and provides a seat for the retrievable valve assembly, wherein various wire line tools may readily pass through the housing for the purpose of performing functions beneath the valve housing, such as perforating the well casing, squeeze cementing, and the like. The valve hereof may be advantageously employed in permanently completed wells wherein it becomes necessary from time to time to remove tubing extensions through the tubing string. In this connection the present invention advantageously provides for the installation of a pair of valve assemblies in a pair of parallel tubing strings leading to a pair of productive well zones.

Another object is to provide a subsurface retrievable valve and housing therefor, which housing is adapted to be connected in the production tubing string and provides a ow area substantially as great as the normal flow area of the tubing string.

The foregoing and further objects and advantages are accomplished in accordance with the present invention by means of a retrievable valve assembly which is actuatable hydraulically by fluid pressure supplied from the earths surface.

Still another object of the invention is to provide a valve mechanism for use in a subsurface location in a well production tubing comprising a housing having a longitudinally extended bore therein for reception of a retrievable valve sub-assembly including al1 sealing and working parts, the housing having ports and means providing a by-pass around the valve sub-assembly when disposed in the passage through the housing, the valve subassembly being adapted to seat in the bore and having a valve sleeve movable from a rst position, whereat the ports in the housing are open, to a second position closing off said ports, but said valve sub-assembly being confined in the housing in such a location as to offer no obstruction to ow. In this connection, the flow of fluid through the assembly is around the valve sub-assembly, as distinguished from through the valve.

Another object is to provide a unitary valve sub-assembly adapted to be received in a ported housing in a subsurface location in well production tubing, said valve subassembly being provided with means engageable by a wire line tool for setting the sub-assembly in the valve housing, said sub-assembly also having means engageable by a wire line tool for retrieving the sub-assembly from the well.

Still another object is to provide a valve insert engageable in a housing in a tubing string, said insert having means to balance off the pressures above and below the insert, whereby such insert is easily removable from the housing.

Other objects and advantages of the invention will be vhereinafter described or will become apparent to those 3,216,501 Patented Nov. 9, 1965 "ice skilled in the art, and the novel features of the invention will be defined in the appended claims.

In the accompanying drawings:

FIG. l is a diagrammatic illustration of an installation of a pair of valves in accordance with the present invention in a dually completed well;

FIG. 2 is an enlarged fragmentary view in horizontal section as taken on the line 2 2 of FIG. l;

FIG. 3 is a detail view in vertical section showing a valve sub-assembly being run into position in a housing which is adapted to be installed in a subsurface location in a production tubing string;

FIG. 4 is a view similar to FIG. 3 but showing the valve sub-assembly seated in the housing and just prior to recovery of the setting tool;

FIG. 5 is a fragmentary vertical sectional View illustratng the valve in an open condition; and

FIG. 6 is a fragmentary vertical sectional view illustrating a retrieving tool engaging the subsurface valve assembly in order to enable recovery of the latter.

Like reference characters in the several views of the drawings and in the following description designate corresponding parts.

Referring rst to FIG. l, there is diagrammatically illustrated a dually completed Well including casing C which has been set in a well bore which traverses a plurality of productive subsurface earth formations F1 and and F2. The formation F1 produces into the casing C through perforations P1 in the casing and production fluids flow to the earths surface through a string of production tubing T1. Subsurface formation F2 produces into the casing through perforations P2 and thence to the surface through tubing T 2. A suitable multiple completion packer designated S1 is sealingly engaged with the casing and with the tubing string T1 and T2 and a second packer S2 is sealingly engaged with the casing C and with the tubing T2 so as to isolate the zones in the casing C adjacent the respective productive formations F1 and F2.

The tubing strings lead to the earths surface where they are supported in a tubing head T3 in a casing head C2. A dual Christmas tree CT is provided at the earths surface including a flow line L1 through which production uids from zone or formation F1 pass and a ow line L2 through which production fluids from formation F2 pass. Suitable control valves V are installed in the Christmas tree as is customary.

Installed in each of the tubing strings is a subsurface valve assembly made in accordance with the invention and generally designated 1, including a housing 2 and a Valve sub-assembly or insert 3. Each housing 2 has a by-pa'ss 4 which is open beneath the insert 3 and above the latter so that production fluids may pass around the respective valve inserts 3 when the latter are open, as will hereinafter more particularly appear.

In the embodiment of the invention as herein disclosed, the subsurface valve is normally closed to prevent the ow of production fluids to the surface, and means are provided for supplying fluid under pressure to the respec. tive valve inserts for the purpose of holding the valve inserts in condition to permit the flow of production uids through the respective tubing strings.

Such lluid under pressure may be supplied in any desired manner, butin the illustrative embodiment of the invention as illustrated in FIG. l, a control tube 5 leads from each valve to the top of the well, where it is connected with a conduit 6. This conduit receives uid under pressure from a line 7 leading from a booster pump 8. Preferably the control tube 5 is originally filled with clean or sweet oil supplied to the booster pumps 8 from seal pots or separator chambers 9 which in turn are in communication through a pipe or conduit 10 with the respective ow lines L1 and L2,which are in communication with the production tubings, as previously described. In addition, a conduit 11 communicates with each of the control tubes and -its pressure supply line 7, each conduit 11 leading to a pressure responsive pilot valve PV which may Ibe either ofthe high or low pressure type adapted to vent the control tubes 5 to atmosphere upon pressure in the respective flow line L1 and L2 to which the pilot valves are connected, falling below or exceeding pressures for which the pilot valve may be set. Furthermore, each of the lines 6 isprovided with a branch 12 to which may be connected a suitable hand pump for applying pressure to the sweet oil or other iiuid in the control tubes 5. From whatever sources, the pressure irnposed on the column of fluid in each controltube is, as will be hereinafter described, adapted to hold the subsurface valve open against theforce applied thereto by production uid pressure tending to close the valve. It will be understood in this connection, that the relative valve areas affected by fluid pressure may be selected and modified to the end that readily available and maintained pressure differentials may be employed to control valve actuation, and furthermore, the density of fluid in the control tube may be varied to conform to various valve areas responsive to such fluid pressure.

A suitable arrangement of manually controlled valves may be employed in the various conduits referred to above which make up the surface installation as may be desired or necessary for the purpose of selectively controlling the ow of fluid or the application of pressure to fluid in the conduits and in the control tubes 5.

As best seen in FIG. 2, in the dual string application ofthe invention, each of the valve housings 2 comprises an elongated cylindrical body, and the by-pass passages 4 are provided in angularly offset conduits 2 which have a cumulative internal flow area preferably at least equal to or greater than the flow area through the cylindrical bodyy 2 so that the passage of Huid around the valve insert 3 is not hampered.V Moreover, in view of the fact that the by-pass conduits are angularly offset relative to one another, there is provided therebetween adequate free space for the passage of the body 2 of a subjacent subsurface valve assembly, so that within the rest of the limited space available within the well casing C, a pair of the valve assemblies of the present invention may be disposed one above the other in a pair of parallel production tubing strings.

Referring now to FIGS. 3 through 6, the details of the housing and the subsurface valve assembly may be more readily understood.

In FIG. 3 it will be noted that the valve housing 2 is connected in the production tubing T as by a pair of couplings 30, and adjacent its upper and lower ends the housing 2 is provided with a series of radially opening ports 31 communicating the tubing T with the by-pass passage 4 through the Iby-pass conduit 2'. Accordingly, the ports 31 and the passage 4 constitute means provided by the body for allowing the flow of uid around the valve insert 3.

The body 2 has therein in sequence one below the other, a groove 32 providing an undercut, downwardly facing shoulder 33, an upwardly facingstop shoulder 34, an annular groove 35, and an annular groove 36, the latter being in the region of the lower ports 31. The inner wall of the body4 2 has a cylindrical zone 37 interrupted 'by the annular channel 35 and a second cylindrical region 38 above the groove 36 as well as a third cylindrical zone 39 below the groove 36. v

The unitary valve insert or sub-assembly 3 is adapted to be received in the body 2 which provides a seat for the insert. This insert 3 includes a body 40 of generally tubular form having a bore 40a, a head 41 thereon which preferably fits closely within the body 2. A skirt 42 is threaded to the lower end of the body 4() of the insert and provides a shoulder @opposed to the head 41 of the body 40. Engaged beneath the head 40 is an annular seal assembly 44 and engaged with the abutment 43 is an annular seal assembly 45. These seal assemblies 44 and 45 are separated by a spacer 46 having a plurality of ports 47 spaced circumferentially therearound and in line with a plurality of radial ports 48 in the insert body 40 which lead into the body bore 40a. It will be noted that the seal assemblies 54 and 55 provide means sealing the insert in said seat.

An elongate downward extension 50 is suitably formed on or connected to the body 40 and in the illustrative embodiment, the extension 50 is threaded into the body and extends downwardly through the skirt 42. The extension 50y constitutes a support shiftably supporting a valve piston 51 including a head 52 and a skirt 53. In axially spaced relation on the piston 51 is a pair of annular seal rings 54 and 55 which are adapted for sealing engagement with the cylindrical zones 38 and 39 of the housing body 2, these seal rings are axially spaced apart a distance greater than the axial dimension of the groove 36 previously described.

The valve piston 51 is provided with a bore in which is disposed an enlarged end 56 at the lower extremity ot the extension 50 of the insert body 40. A seal ring 57 is interposed between the valve piston 51 and the enlarged end 56 of the extension 50 and another seal ring 59 is interposed between the downward extension 50 of the insert body 40 and the head 52 of the valve piston 51, so that when the insert 3 is seated in the housing 2, fluid under pressure supplied from control tube 5 to the space between the seal rings 57 and 59 will act yupon a fluid pressure responsive face 58 of the piston head 52 to urge the piston upwardly relative to the supporting extension 50. Means are preferably provided for normally forcing the piston 5 downwardly, and illustratively the piston 51 is preferably normally spring biased downwardly as by means of a spring 60 surrounding the supporting extension 50. At its lower extremity the spring 60 is engaged with the upper end of the head 52 of the valve piston and at its upper extremity the spring is engaged with the lower end of the insert body 40 within the skirt 42.

The extension 50 of the insert 3 is provided with an elongated bore 61 closed at its lower end by plug 62 and closed at its upper end byV plug 63. The extension is provided with a radial port 64 which leads into the zone lying between the above mentioned seal rings 57 and 59. At its other end the extension 50 is provided with a port 65 which communicates with an annulus 66 internally of the body 40 of the insert and the body in this region is provided with the plurality of radial ports 48 previously referred to as communicating with the ports 47 in the sealing ring spacer 46.

In addition, the insert body extensions 50 is provided with a bore 6'7 which is open at its lower end andwhich communicates through a radial port 68 with the outside of the extension 50 for the purpose of enabling the valve piston 51 to be loaded downwardly by well fluid pressure when installed, as will be hereinafter described. At its upper extremity the bore 67 in the extension 50 is pro vided with a plug 69 having a frangible tip 70 extending into the bore 40a of -the insert body 40.

As shown in FIG. 3, the insert body 40 is adapted to be connected to a setting tool generally designated ST and having a body 72 provided at its lower end with' a stem 73 which is adapted to project into the upper eX- tremity of the head 41 of insert body 3vwhere it is xedly secured as by a pair of shear pins 74 removably retained in place by means of set screw plugs 75.

Extending upwardly from the body head 41 is a plurality of latch fingers 76 each having outwardly extended shoulders 77, fishing teeth 78 and inner retainer lugs 79. As shown in FIG. 3, the retainer lugs 79 of the respective fingers 76 are engageable in a groove 80 formed on the body of the setting tool so that the lingers 76 are held in an inwardly flexed or stressed position. With the retainer shoulders 79 engaged in the groove 80, the shear pins 74 may be installed to releasably secure the setting tool ST to the insert body 3. At its upper extremity the setting tool has appropriate and conventional means for connection to a rope socket RS of a wire line in the usual manner, or if desired, the upper end of the body may be connected to a weighted sinker bar which in turn may be connected to the wire line rope socket, as is well known in the art.

In FIG. 3, the insert assembly is shown as supported on the setting tool ST and as being lowered into position in the valve housing 2. Downward movement of the insert 3 will be halted when the insert body head 41 abuts with the internal shoulder 34 in the housing 2, as shown in FIG. 4, and subsequent downward movement of the setting tool ST will cause the shear pins 74 to be sheared, thus allowing further downward movement of the setting tool until such time as a shoulder 81 thereon abuts with the upper end of the insert body head 41. This slight further downward movement of the setting tool allows the retainer plugs 79 on latch lingers 76 to be disengaged from the setting tool body groove 80 so that the lingers will llex outwardly as shown in FIG. 4, and the latching shoulder 77 thereof will engage with the ldownwardly facing shoulder 33 of the annular groove 32 inside the housing 2. The setting tool ST may then be removed and the valve will be securely latched in place, with the valve piston 51 disposed in the position shown in FIG. 4, that is, in a position for closing o the flow of lluid upwardly through the tubing T into the by-pass passage 4. It will be noted that the valve piston is hydraulically urged or biased to a closed position when installed, inasmuch as well lluid pressure is imposed on the upper face of the piston head 52 which has an elfective annular area A, through the elongated passage 67 in the piston supporting extension 50 and radial port 68, while well fluid pressure also acts upon the annular piston area A-B biasing the piston upwardly. It will also be noted that with the valve insert 3 in vthe position shown in FIG. 4, fluid in the control tube 5 has access to the face 58 of the valve piston 52 via the annular groove 35 within the housing 2, the radial port 47 in the lield spacer 46, the radial ports 48 in the body 40 and the radial ports 65 in -the upper end of body extension 50, longitudinal passage 61 in the extension 50 and radial ports 64 in the latter which lead to the face 58. This face 58 has an annular area B responsive to control lluid pressure from tube 5.

Hence, disregarding seal and fluid friction as insignificant, the valve piston responds according to the formula: P1(A-B)IP2 B-P1 A|-S where P1 is well pressure below the valve and P2 is control pressure supplied from the surface and S is the Iforce of spring 60. Hence, if P2 is equal to P1, the valve will be held closed by the spring 60. Where P2 is less than P1, the valve would remain closed without spring force S. Where P2 is greater than P1, the valve would be biased open without the spring. With the spring present, P2 need only slightly exceed P1 by an X factor in the equation XB:S to bias the Valve open. Therefore, application of well production pressure at the earth surface to the hydrostatic head in tube 5 may be employed as a means for holding the valve open so long as production pressure is not vented to atmospheric either manually or by pilot Valve PV or by damage to the surface equipment. Otherwise, the source 8 may be employed to supply such fluid pressure to open the valve.

As shown in FIG. 5, the application of lluid under pressure, from whatever source, through the control tube 5 to the liuid pressure responsive valve piston face 58, will shift the valve piston 51 upwardly, compressing the spring 60 until the piston 51 abuts with the lower extremity of the skirt 42 on insert body 40, at which time fluid may flow upwardly through the lower ports 31 into the by-pass 4 around the valve insert, through upper ports 31 and on upwardly through the tubing. Such 6 fluid pressure may be supplied by the previously described pressure and control system of FIG. l, or by such other pressure supplying system as may be desired.

Referring to FIG. 6, a retrieving tool RT is illustrated, this tool being adapted to be supported upon a wireline having a rope socket RS as previously described. The retrieving tool RT includes a body on the lower end of which is disposed an enlarged member 91 which is engageable with the upper face of the head 41 of insert body 40. An extension 92 is provided on the enlarged member 91 and is adapted to move into the bore 40a of the body 40 and is provided with a conically recessed end 93 engageable with the frangible tip 70 of the litting 69 so as to fracture the tip from the litting, thus, when the valve is closed, allowing well lluid under pressure to pass upwardly through the bore 69 into the housing above the insert, thereby substantially balancing olf the pressure differential across the insert and allowing its ready removal.

Carried by the retrieving tool body 90 is an inverted cup-like lishing member 94 having internal teeth 95 enga-geable with the fishing teeth 78 of the spring latching lingers 76. Preferably, the lishing member 91 has a beveled surface at its lower extremity designated 96 and extending radially so as to engage the uppermost extremity of the latching lingers 76 and wedge the latter inwardly upon further downward movement of the lishing member 94 from the position shown in FIG. 6. Such downward movement is enabled subsequent to fracturing of the frangible tip 70 from the litting 69 by means of a shear pin 97 which connects the retrieving tool body 90 to an adapter 98 having a bore 99 in which a head 100 of the retrieving tool is disposed and retained by the shear pin 97. Subsequent to shearing of the pin 97, the fishing member 94 will move downwardly into engagement with the teeth 98 of the latch linger 76 while the latching shoulders 77 thereof will be moved inwardly from engagement with the downwardly facing shoulders 73 in the body `0r housing 2. The insert 3 may thus be retrieved.

From the foregoing it will be apparent that the present invention provides a readily retrievable insert type subsurface valve and housing therefor which is adapted to control the ow of production lluids from a well from a subsurface location remote from the hazards of sabotage or the elements in the case of olishore wells, as well as a valve assembly which enables unrestricted flow of production liuids while enabling service of the well without costly removal of the well head equipment, such valve being well suited for use in dually completed wells as well as wells producing from but a single zone.

While the specific details of an illustrative embodiment lof the invention have been herein shown and described, changes and alterations may be resorted to with,- out departing from the spirit thereof as defined in the appended claims.

I claim:

1. A shut-olf valve for wells, comprising: an elongated housing having means providing a by-pass passage; a seat in said housing; a valve insert; means for releasably retaining said Iinsert in said seat; said insert including a body; means sealing said insert body in said seat; a valve member at one side of said sealing means movable from a position allowing llow through said bypass passage to a position preventing such liow; means supporting said valve member on said body for such movement; means including liuid pressure responsive surfaces on said member vfor moving said valve member to said positions; and said body having means including a passage therethrough for enabling hydraulic balancing of said insert when said body passage is open; and closure means provided for selectively opening said body passage to permit said hydraulic balancing to occur through said sealing means.

2. A shut-off valve for wells, comprising: an elongated housing vertically connectable in a string of tubing; said housing having a port leading therefrom; valve insert means; means removably retaining said valve insert means in said housing; said valve insert means including a valve member movable from a position whereat said port is closed to a position Whereat said port is open; said valve member having surfaces responsive to fluid pressure for moving said valve member to said positions; said valve insert means having means above said port sealing said insert in said housing and also having a passageway leading from one side of said sealingmeans to the other for by-passing liuid from one side of said insert means to the other whereby said insert means is hydraulically balanced; and closure means at the upper end of said passageway closing said passageway and operable by a retrieving tool for opening said passageway.

3. A shut-olir valve as defined in claimy 2, wherein said closure means comprises a tting having a frangible portion engageable by said retrieving tool.

4. A shut-olf valve for wells, comprising: an elongated housing vertically connectable in a string of tubing; said housing having means providing a by-pass passage outside said housing; a first port leading into said by-pass passage from said housing at the lower end, thereof and a port leading into said housing from said by-pass pas- Vsage at the upper end thereof; a control fluid inlet leading into said housing between said ports; a valve insert removably engageable in said housing between said ports; means providing a seal between said insert and saidhousing; said insert and said housing having means for releasably latching said insert in said housing; said insert having a valve member; means supporting said valve member for movement from a position above said lirst port to a 'position to close said rst port; said valve member having face means responsive to well fluid pressure in said housing and to control iluid pressure supplied through said inlet for moving said -member to said positions; means for conducting control fluid to said face means from Ysaid control lluid inlet; a passageway extending through said insert lfrom below said valve member to the upper end of said insert; and closure means at the upper -end of said passage and openable to allow balancing of the pressure across said insert when said valve member is in position closing said rst port.

5. A shut-off valve as defined in claim 4, wherein said valve member is a piston having means for sealing engagement with said housing in axially spaced locations;

fsaid sealing means straddling said port when said piston is in a position to close said port.

6. In a multiple completion well having a pair of 4parallel tubing strings extending downwardly in a well bore from the top of the well and communicating with Well uids in separate productive well zones; liuid pres- Vsure actuatable valve means in each of said tubing strings; each of said valve means including a housing having a bore therethrough; means providing a by-pass passageway exending longitudinally of said housing exteriorly thereof; a valve insert in said bore; means providing a seal in said bore between said insert and said housing;

means for releasably la-tching said insert in said bore; said insert having a valve element shiftable from a position closing said by-pass to a position where said by-pass is open; means including faces on said valve element responsive to well fluid pressure and to control fluid pressure for holding said valve element in said by-pass closing position and for moving said valve element to said posi- .tion where said by-pass is open; a source of control fluid under pressure leading from the top of -the well to each of said valve means; and said means providing a by-pass comprising by-pass conduit means extending along said .housing and having a by-pass llow area substantially equal to the ow area of said tubing; the housings of the respective valve means being longitudinally spaced one from the other; each conduit .means forming with .its housing a S clearance space within the well bore through which the tubing string of the other valve means extends.

7. Apparatus as defined in claim. 6, wherein said means providing a by-pass comprises a pair of conduits extending along said housing in angularly spaced relation thereon and defining a space therebetween for said tubing string of said other valve means to extend.

8. In a multiple completion well having a pair of parallel tubing strings extending downwardly in a well bore from the top of the well and communicating with well uids in separate productive well zones; fluid pressure actuatable valve means in a section of each of said tubing strings including a housing and a shiftable valve element in said housing having a surface responsive to well tluid pressure for moving said element in one direction and a surface responsive to control liuid pressure for moving said element in the other direction; means for supplying control Huid under pressure from the top of the well to said latter surface; means defining a bypass for establishing communication between the sections of said tubing string of each of said valve means when said valve element is moved in one of said directions; and said means providing a by-pass comprising by-pass conduit means extending along said housing and having a by-pass flow area substantially equal to the flow area of said tubing; the housings of the respective valve means being longitudinally spaced one from the other; each conduit means forming with its housing a clearance space within the well bore through which the tubing string of the other valve means extends.

9. Apparatus as dened in claim 8, wherein said means providing a by-pass comprises a pair of conduits extending along said housing in angularly spaced relation thereon and defining a space therebetween for said tubing string of said other valve means to extend.

10. A subsurface shut-off valve for multiple completion wells comprising: an elongated housing adapted to be connected in a string of well production tubing in a well bore; valve means within said housing; means providing a seal between said valve means and saidhousing; longitudinally spaced ports in said housing at opposite ends of said valve means; and means defining a by-pass passageway extending longitudinally of said housing externally thereof in communication with said longitudinally spaced ports; said means defining a by-pass forming with said housing a clearance space within the well bore through which a tubing of another valve may ex- -tend upon installation of a pair of such valves in a multiple completion well, said valve means being arranged to open and close at least one of said ports, said by-pass passageway having a cross-sectional area substantially equal to the cross-sectional area of said well production tubing.

11. A valve as deined in claim 10, wherein said means dening a by-'pass comprises a pair of conduits extending along said housing externally thereof in angularly spaced relation and defining therebetween said clearance space for said tubing of said other valve.

12. A valve insert for insertion 'in a complemental valve housing, comprising; an elongated body member having means for retaining the same in said housing; a valve piston; means shiftably supporting said valve piston on one end of said body member; said body having a port adjacent said piston; sealingmeans forming a seal between said body member and said housing at opposite sides of said port; said body member having a passage leading to said one end and incommunication with said port; said piston having a face responsive to fluid pressure supplied through said passage for moving-said piston in one direction; said Ibo-dy having an inlet leading to said passage; a second passage extending through said body; andmeans normally closing said second passage and adapted to be opened so as to `allow fluid to pass through said body to opposite ends thereof.

`13. A valve insert as defined in claim 12, wherein said means normally closing said second passage cornprises a plug having a frangible tip; said plug having an opening therein extending into said tip.

14. A valve insert as defined in claim 12, wherein said means for opening said second passage comprises a fitting having a frangible tip; said fitting having an opening eX- tending therethrough into said tip; in combination with a tool to remove said insert from the housing therefor; said tool having means engageable with said frangible tip for separating the latter from said fitting; and said tool and said insert having cooperatively engageable means for connecting said tool to said insert.

15. In a shut-off valve for wells: a housing adapted to be connected in a string of well production tubing and having a pair of longitudinally spaced ports; means dening a by-pass passage exteriorly of said housing and communicating with said ports; uid pressure operated valve means removably disposed within said housing including a shiftable valve member movable from a position above the lowermos-t of said pair of ports, to a position closing said lowermost port; and means for supplying fluid under pressure from the top of said well to said valve element for controlling the position of said valve element.

16. A shut-01T valve for wells, comprising: well production pipe extending downwardly in the well and communicating with well fluid; fluid pressure actuatable valve means in said pipe; said valve means including a housing having a bore therethrough of a size substantially equal to the inside diameter of said pipe; a valve insert in said bore; means in said bore providing a seal between said insert and said housing; said insert and said housing having means for releasably latching said insert in said bore; said housing having an outlet port below said insert for allowing well fluid to by-pass said housing; said insert having a valve element shiftable from a position closing said port to a position above said port where said port is open; means including faces on said valve element responsive to well fluid pressure and to control iluid pressure for respectively holding said valve element in said port closing position and for moving said valve element to said position where said port is open; said insert including a support; said valve element comprising a piston shiftably carried by said support; longitudinally spaced sealing means interposed between said support and said piston; said support having means for allowing well fluid under pressure to by-pass said piston when said piston is in said position closing said port; a source of control fluid under pressure leading from the -top of the Well to said housing; said insert having means including a passageway in said support for directing said control uid to the space between said spaced sealing means; and said piston face responsive to control fluid pressure being located in said space between said sealing means.

17. A shut-olf valve for wells, comprising: well production pipe extending downwardly in the well and communicating with well fluid; uid pressure actuatable valve means in said pipe; said valve means including a housing having a bore therethrough of a size substantially equal to the inside diameter of said pipe; a valve insert in said bore; means in said bore providing a seal between said insert and said housing; said insert and said housing having means for releasably latching said insert in said bore; said housing having an outlet port below said insert for allowing well uid to by-pass said housing; said insert having a valve element shiftable from a position closing said port to a position above said port where said port is open; means including faces on said valve element responsive t'o well iluid pressure and to control fluid pressure for respectively holding said valve element in said port closing position and for moving said valve element to said position where said port is open; a source of control lluid under pressure leading from the top of the well to said housing; said insert having means for directing said control iluid to said valve element; said housing being provided with a second port disposed above said insert; and means providing a by-pass passageway between said ports exteriorly of said housing.

18. A valve mechanism comprising: an elongated housing; said housing having a port for the passage of fluid from within said housing to the exterior thereof; a valve insert in said housing; means forming a seal between said insert and said housing; means releasably latching said insert in said housing; said insert having a valve element shiftably carried thereby for movement between positions at which said port is open and closed; said valve element having a face responsive to uid pressure to urge said element to the position in which said port is closed and another face responsive to control uid pressure for shifting said element to the position in which said port is open; said insert having means providing a control fluid inlet and a passage leading to said another face of said valve element; and said housing having a port leading to said inlet in said insert; said insert including a passageway extending therethrough; and closure means closing said passageway and openable so as to allow uid pressure in said housing to be balanced across said insert.

19. A shut-off valve for wells comprising: a longitudinally extended housing having means at its opposite ends for connection in a string of tubing; said housing having a bore therethrough; a valve insert disposed in said bore; means lproviding a seal between said insert and said housing in said bore; coengageable means in said housing and on said insert for removably retaining said insert in place in said bore; said housing having a lateral passage spaced longitudinal-ly from an end of said insert; said insert having an elongate extension projecting from said end of said insert; a tubular piston slidably disposed on said extension and having a portion projecting beyond the free end of said extension and movable between positions at which said piston closes said passage and at which said passage is opened; a pair of axially spaced sealing means providing axially spaced seals between said piston and said extension and forming therebetween a pressure chamber; said piston having a surface exposed to pressure in said pressure chamber for urging the piston inwardly of said extension; a second surface on said piston; means including a first passageway extending through said extension and communicating with said pressure chamber for supplying control fluid pressure to said pressure chamber; and means including a second passageway in said extension for conducting housing pressure to said second surface past said seal between said insert and said housing.

References Cited by the Examiner UNITED STATES PATENTS 1,193,769 8/ 16 Cushing 166-224 1,255,147 2/ 18 Fletcher 166-72 XR 2,092,819 9/37 Tennant 251-282 X 2,128,253 8/38 Johnson 166-45 X 2,352,612 7/44 Boynton 166-125 2,726,724 12/ 55 Wilhoit et al. 166-45 2,780,290 2/57 Natho 166-72 2,785,754 3/57 True 166-45 2,798,559 7/57 Fredd 166-125 2,902,093 9/59 Brown 166--224 X 3,002,562 10/61 Carothers 166-125 3,002,566 10/61 Bostock 166-125 3,078,923 2/63 Tausch 166-72 3,089,431 5/63 Davis 137-155 X FOREIGN PATENTS 49,950 12/ 09 Switzerland.

CHARLES E. OCONNELL, Primary Examiner.

BENJAMIN BENDETT, Examiner. 

1. A SHUT-OFF VALVE FOR WELLS, COMPRISING: AN ELONGATED HOUSING HAVING MEANS PROVIDING A BY-PASS PASSAGE; A SEAT IN SAID HOUSING; A VALVE INSERT; MEANS FOR RELEASABLY RETAINING SAID INSERT IN SAID SEAT; SAID INSERT INCLUDING A BODY; MEANS SEALING SAID INSERT BODY IN SAID SEAT; A VALVE MEMBER AT ONE SIDE OF SAID SEALING MEANS MOVABLE FROM A POSITION ALLOWING FLOW THROUGH SAID BYPASS PASSAGE TO A POTIION PREVENTING SUCH FLOW; MEANS SUPPORTING SAID VALVE MEMBER ON SAID BODY FOR SUCH MOVEMENT; MEANS INCLUDING FLUID PRESSURE RESPONSIVE SURFACES ON SAID MEMBER FOR MOVING SAID VALVE MEMBER TO SAID POSITIONS; AND SAID BODY HAVING MEANS INCLUDING A PASSAGE THERETHROUGH FOR ENABLING HYDRAULIC BALANCING OF SAID INSERT WHEN SAID BODY PASSAGE IS OPEN; AND CLOSURE MEANS PROVIDED FOR SELECTIVELY OPENING SAID BODY PASSAGE TO PERMIT SAID HYDRAULIC BALANCING TO OCCUR THROUGH SAID SEALING MEANS. 